I have used this for a couple of years:click here
It is free, but to get the 'incremental' back up facility it costs about £28.
It makes the target drive bootable and every time the PC boots up it gives you the option to boot from the cloned drive before Windows starts.
So if C is corrupted just reboot and start with the other drive. No messing with making bootable CDs etc.
Without the incremental version it will do a complete back up each time which will take much longer. Mine takes about 3 mins to do an incremental
from 100gb of files.